1. Field of the Invention
The present invention relates to a circuit component built-in module. In particular, the present invention relates to a circuit component built-in module in which, for example, an active component is arranged in an internal portion of an insulating substrate.
2. Description of the Prior Art
Recently, with a demand for high performance and miniaturization of electronic equipment, high-performance and high-density circuit components have been increasingly desired. This leads to a demand for a circuit substrate commensurate with high-performance and high-density circuit components.
The formation of a multilayered circuit may be a solution to achieve higher-density circuit components. However, a conventional glass-epoxy substrate requires a through-hole structure to form a multilayered circuit, to that is hardly a solution for high-density mounting. Therefore, a connection method using inner via holes that can connect between wiring patterns of LSIs or circuit components in the shortest distance has been developed in various fields in order to achieve higher density packaging.
The connection method using inner via holes allows electrical connection only between the layers necessary to be connected through a connection called an inner via, so that circuit components can be mounted with high density (U.S. Pat. No. 5,481,795, U.S. Pat. No. 5,484,647, and U.S. Pat. No. 5,652,042)
However, a substrate that has been conventionally used in the inner via connection comprises a resin based material, which has low thermal conductivity. Therefore, the problem of a low thermal conductivity is posed. In a circuit component built-in module, the higher density mounting of circuit components leads to an increased demand for releasing heat that has been generated in the components. However, the conventional substrate cannot sufficiently release heat, and therefore, the reliability of the circuit component built-in module deteriorates.